Why does the car engine shake when the air conditioner is turned on?
2 Answers
The most common reason for engine shaking when the air conditioner is turned on is a dirty throttle valve, which affects the engine. Turning on the air conditioner at this time increases the engine idle load, leading to steering wheel vibration. Therefore, cleaning the throttle valve can prevent this issue. Below is an introduction to the throttle valve: 1. The throttle valve is a controllable valve that regulates air intake into the engine. After air enters the intake pipe, it mixes with gasoline to form a combustible mixture for combustion. The throttle valve is one of the most critical components in an EFI (Electronic Fuel Injection) engine system. Its upper part connects to the air filter, and the lower part connects to the engine block, functioning as the throat of the car engine.
This is a common issue I often encounter. The engine shaking when the AC is on is mainly because the AC compressor increases the engine load, meaning the engine has to handle more tasks simultaneously. If the engine itself has minor issues, such as aging spark plugs failing to ignite or problematic ignition coils causing uneven combustion of the air-fuel mixture, it can lead to imbalanced combustion and make the car shake. Another possible cause is improper air-fuel ratio regulation, where the mixture isn't balanced, and the computer control system fails to adjust in time. I've also experienced cases where vacuum tube leaks caused this issue, as the AC system relies on vacuum support, and leaks can disrupt the engine's smooth operation. I recommend first checking the spark plugs and ignition coils for any damage. If the problem persists after replacing them, it's necessary to inspect the AC compressor or visit a professional shop to diagnose the engine control unit. Regular engine maintenance and carbon deposit cleaning can prevent this issue. Don't underestimate it—prolonged neglect can affect driving safety and increase fuel consumption.
